禁用源自于scipy的警告 [英] Disable warnings originating from scipy
问题描述
当我将函数整合到不同的参数值时，我经常会遇到如下错误：
As I integrate a function at different parameter values, I often encounter errors like:
lsoda-- warning..internal t (=r1) and h (=r2) are
such that in the machine, t + h = t on the next step
(h = step size). solver will continue anyway
虽然我了解错误的技术方面，但我感到失落如何将它压制成 stdout 。我查看了 numpy.seterr（），但是由于此错误消息似乎是从底层C / Fortran代码生成的，因此它没有任何效果。而 python script.py> / dev / null 是有效的，它显然也隐藏了可能打印的其他有用的信息。
While I understand the technical aspects of the error, I am at a loss as to how I might suppress it from being printed to stdout. I've looked into numpy.seterr(), but as this error message appears to be generated from the underlying C/Fortran code it has no effect. And while python script.py > /dev/null is effective, it obviously also hides other, helpful information that might be printed.
有没有办法禁用这些code> lsoda 警告和错误，或以其他方式阻止他们被打印到 stdout ？
Is there some way of disabling these lsoda warnings and errors, or otherwise preventing them from being printed to stdout?
推荐答案
使用 JF Sebastian的stdout_redirected ，您可以将文件描述符级别上的stdout 重定向到os.devnull。
Using J.F. Sebastian's stdout_redirected, you could redirect stdout at the file descriptor level to os.devnull.
with stdout_redirected():
soln2 = integrate.odeint(f, y2, t2, mxstep = 5000)
在 with-statement 之外，stdout仍然被打印。在 with-suite 中，stdout被压制。
Outside of the with-statement, stdout still gets printed. Inside the with-suite, stdout is suppressed.
例如，这里是 Caeiro的odeint示例，其中的lsoda警告被压制为 stdout_redirected 。
For example, here is Caeiro's odeint example whose lsoda warnings are suppressed with stdout_redirected.
import os
import sys
import contextlib
import numpy as np
import scipy.integrate as integrate
from numpy import pi
def fileno(file_or_fd):
fd = getattr(file_or_fd, 'fileno', lambda: file_or_fd)()
if not isinstance(fd, int):
raise ValueError("Expected a file (`.fileno()`) or a file descriptor")
return fd
@contextlib.contextmanager
def stdout_redirected(to=os.devnull, stdout=None):
"""
https://stackoverflow.com/a/22434262/190597 (J.F. Sebastian)
"""
if stdout is None:
stdout = sys.stdout
stdout_fd = fileno(stdout)
# copy stdout_fd before it is overwritten
#NOTE: `copied` is inheritable on Windows when duplicating a standard stream
with os.fdopen(os.dup(stdout_fd), 'wb') as copied:
stdout.flush() # flush library buffers that dup2 knows nothing about
try:
os.dup2(fileno(to), stdout_fd) # $ exec >&to
except ValueError: # filename
with open(to, 'wb') as to_file:
os.dup2(to_file.fileno(), stdout_fd) # $ exec > to
try:
yield stdout # allow code to be run with the redirected stdout
finally:
# restore stdout to its previous value
#NOTE: dup2 makes stdout_fd inheritable unconditionally
stdout.flush()
os.dup2(copied.fileno(), stdout_fd) # $ exec >&copied
#Constants and parameters
alpha=1/137.
k=1.e-9
T=40.
V= 6.e-6
r = 6.9673e12
u = 1.51856e7
#defining dy/dt's
def f(y, t):
A, B, C, D, E = y
# the model equations
f0 = 1.519e21*(-2*k/T*(k - (alpha/pi)*(B+V))*A)
f1 = ((3*B**2 + 3*C**2 + 6*B*C + 2*pi**2*B*T + pi**2*T**2)**-1
*(-f0*alpha/(3*pi**3) - 2*r*(B**3 + 3*B*C**2 + pi**2*T**2*B)
- u*(D**3 - E**3)))
f2 = u*(D**3 - E**3)/(3*C**2)
f3 = -u*(D**3 - E**3)/(3*D**2)
f4 = u*(D**3 - E**3)/(3*E**2) + r*(B**3 + 3*B*C**2 + pi**2*T**2*B)/(3*E**2)
return [f0, f1, f2, f3, f4]
t = np.linspace(1e-15, 1e-10, 1000000) # time grid
y2 = [2e13, 0, 50, 50, 25]
t2 = np.linspace(1.e-10, 1.e-5, 1000000)
with stdout_redirected():
soln2 = integrate.odeint(f, y2, t2, mxstep = 5000)
lsoda写入stdout的警告被抑制。
The warnings which lsoda writes to stdout are suppressed.
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